RESEARCH AND USUAL CARE PREVENTION EFFORTS ACROSS PSYCHIATRIC DIAGNOSES
Dr. Katherine Comtois reviewed research on suicide prevention interventions and treatment. She discussed methodological issues including treatment as usual, the relationship between suicide and mental illness, and the efficacy of pharmacological and behavioral treatments; she also made recommendations for future research. In general she reported finding very few studies, with broad variability making it hard to compare results across studies. The group discussed the methodological limitations and the implications for this field.
The few randomized controlled trials testing treatment efficacy are plagued with methodological problems.
Methodological Issues. Sample size is a problem for most studies. This is especially problematic since suicidal behaviors occur at a low frequency, making larger samples necessary to measure any treatment effect. Another problem according to Dr. Comtois, is nomenclature. There is no universally accepted nomenclature in the field. Terms such as parasuicide are defined differently across studies making comparisons difficult. Another complicating factor is that some studies use an “admission versus no admission” measure. This dichotomy obfuscates the difference between a psychiatric crisis and suicidal behavior.
The conference attendees noted that the systematic exclusion of high risk patients from suicide prevention trials is a complex and important ethical and methodological problem. It is unethical to place someone at imminent risk of suicide in a randomized trial where they might get placebo treatment. Further complicating the issue, the definition of “high risk” varies across studies and is often not described beyond “in need of imminent hospitalization,” according to Dr. Comtois. It is of great concern that only those studies including high risk patients demonstrated significant effects of treatment in reducing suicide. Dr. Comtois explained that this sets up two possible biases in the research literature. Those studies reporting treatment effects may have them due to the high risk group, or conversely, the lack of treatment effect could be due to the inability to reduce the suicide risk any further in the lower risk population.
Thirty-six percent of the studies that specifically targeted deliberate self harm, parasuicide, and the majority of depression studies exclude individuals identified at high risk.
The clinical setting of a suicide intervention study has consequences for its interpretation. Clinical research often occurs in academic hospital settings, which often differs from the more usual clinical situations. “Usual care” research describes what treatment-as-usual is for different
populations. Dr. Comtois noted that it is important to know what patients are actually receiving via health services in order to assess opportunities for improved outcomes. In addition, to develop prevention efforts that can be applied in real-life settings and have efficacy outside of the research setting, the intervention’s setting needs to be considered.
Dr. Comtois reported that most of the studies were based on epidemiological data, primarily from Europe where more comprehensive public data bases are kept. As with the treatment efficacy literature, she reported the body of data to be woefully small and fraught with methodological problems. Often the “treatment-as-usual” condition was not measured. This is a particular problem in studies of outpatient services. Where treatment is described, there are vast variations in treatment services across and within countries and over time.
Suicide and Mental Illness. There is a high but not complete overlap between suicide and mental illness. Dr. Comtois questioned if “treating the psychiatric disorder is not only necessary, but also sufficient to reduce suicide.” In some studies, according to Dr. Comtois, “there is a close relationship between a reduction in the symptoms and a reduction in suicidality, but that is not universal.” The workshop attendees discussed studies showing a reduction in suicidality without a reduction in depression or vice versa.
The workshop attendees also discussed pharmacological studies showing significant reductions in suicide, even when depressive symptoms are not similarly reduced. Dr. Jamison described a recent meta-analysis on the efficacy of lithium. They found an over 8-fold reduction in suicide risk with prophylactic lithium treatment. Other studies of antipsychotic medications have also found significant reductions in suicide, according to Dr. Comtois. However, not all psychiatric medications are efficacious in reducing suicide, as indicated by some recent meta-analyses of anti-depressants. The lack of efficacy is again confounded by the exclusion of those at high risk for suicide.
Behavioral Interventions. Dr. Comtois reported variability in the behavioral intervention literature. Some interventions reported significant reductions in suicide, others reported trends, and still other studies reported no effect. She underscored the difficulty in comparing studies because of methodological differences across studies, inconsistencies in nomenclature, and exclusion of people at high risk.
Dr. Comtois described the only study reporting a significant reduction in completed suicide. Patients who refused treatment after a suicide attempt were entered into a study in which the “experimental” group received letters (contact) while the “control” group did not (non-contact). Dr. Comtois reinforced the importance of the non-demanding quality of this intervention. People in the contact group received a letter once per month for the first year, every 2 months in the second year, and one every third month for years 3 through 5. After the fifth year, the letters were discontinued. The patients were followed for 15 years. Dr. Comtois described that at year 2 the contact group had significantly reduced suicide rates compared to the non-contact group. This difference continued until year 14, at which point the rates in both groups were similar. Dr. Comtois posed the question: would continuing contact past the 5 years continue to reduced suicide rates?